for Surround Model 76D Central Controller and Model 77 Control Console User Guide Issue 13, December 2020 This User Guide is applicable for systems consisting of: Model 76D: serial number M76D-01151 and later with software version 4.20 and higher and FPGA version 4.12 and higher; Model 77: serial number M77-00151 and later with software version 4.20 and higher © 2020 by Studio Technologies, Inc., all rights reserved www.studio-tech.
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for Surround Table of Contents Introduction ................................................................... 5 Installation .................................................................... 9 Configuration ................................................................16 Operation ......................................................................38 Technical Notes ............................................................45 Specifications .......................................................
for Surround This page intentionally left blank. Issue 13, December 2020 Page 4 Model 76D/77 User Guide Studio Technologies, Inc.
for Surround Introduction What This User Guide Covers This User Guide is designed to assist you when installing and using the Model 76D Central Controller and one or more associated Model 77 or Model 71 Control Consoles. Overview As creating and distributing multi-channel surround (5.1) and stereo audio material has become a day-to-day reality, the ability to simply and effectively monitor these sources is imperative for recording, postproduction, and broadcast facilities.
for Surround real-time selection as desired. A number of different signals can serve as the Model 76D’s digital audio timing reference. For synchronization with a master timing reference a dedicated source of word clock, DARS (AES11), bi-level video, or tri-level video can be connected. Alternately, the L/R connection of the actively selected surround or stereo input source can serve as the timing reference.
for Surround Channel mute/solo Mute/solo mode Downmix Input source select Monitor output level display Post-fader surround monitor output • Surround/stereo • Reference level • Mute all • Dim • Rotary level control Figure 3. Model 77 Control Console Front Panel be separated and then routed to the subwoofer loudspeaker. Several of the bass management functions can be configured to match the requirements of specific installations.
for Surround LFE content before routing the sum to the subwoofer output. The post-fader surround and stereo monitor output levels can be controlled by way of a large, easy-to-use rotary control. The control, actually a digital encoder, allows level selection in precise 0.5-dB steps. The auto mute all function causes the post-fader surround and stereo monitor output channels to automatically mute whenever the output level control reaches maximum attenuation.
for Surround functions, talkback or slate activity from an audio console or other communications system can control the level of the postfader surround and stereo monitor outputs. Installation In this section you will be installing the Model 76D Central Controller in an equipment rack. Connections to the digital audio inputs and digital monitor outputs will be made. A dedicated digital audio timing reference signal can be connected to the sync input.
for Surround There is, however, an exception worth noting. Circuitry associated with stereo input C has sample rate conversion (SRC) capability, allowing virtually any digital audio signal to be connected. A signal connected to stereo input C can have an independent sample rate and timing reference and still be monitored correctly. Refer to the Technical Notes section of this guide for a detailed review of the SRC capability.
for Surround A cable assembly with a 25-pin male D-sub on one end and the desired connectors on the other end will be used for connecting to the digital monitor outputs. The D-subminiature connector follows the TASCAM® wiring convention, organizing the 25 pins into eight groups of three pins each; one pin remains unused. Each set of three pins provides an independent interface. In the analog world this would allow eight audio signals to be transported.
for Surround Pre-Fader Surround Monitor Output The pre-fader surround monitor output channels are intended to connect to metering, measurement, or other signal monitoring equipment that requires uninterrupted, full-level digital audio signal sources. Stereo Input C Direct Monitor Output The stereo input C direct monitor output is intended for use in site-specific applications. It provides an uninterrupted, full-level digital audio signal source that is post-SRC and input delay in the signal chain.
for Surround to be high-impedance (“floating”) or terminated with an impedance of 75 ohms. A sync source that is dedicated for use by the Model 76D’s sync input will typically have input termination enabled. If the sync signal connected to the Model 76D is being connected (“multed”) to other inputs it may be desirable for the termination to be disabled. A general “rule of thumb” is that termination should be applied only at the location of the last physical device using a sync signal.
for Surround Signal Pin Direction Data + (RS-485) 1 To/From Models 77/71 Data – (RS-485) 6 To/From Models 77/71 Data Shield 2 To/From Models 77/71 DC + (12 V) 4 To Models 77/71 DC – (12 V Return) 9 To Models 77/71 DC Power Shield 5 To/From Models 77/71 Note: Connector type on Model 76D is 9-pin female D-subminiature (DE-9F). Connector uses 4-40 threaded inserts for locking with mating plug. Figure 6.
for Surround tween all the units will be multed. A custom cable implementation requires just four pins to be connected: pin 1 (data +), pin 6 (data –), pin 4 (DC +), and pin 9 (DC –). To make installation simple, a “bus” cable assembly can be created using a short length of ribbon cable with one male and multiple 9-pin female D-subminiature insulation-displacement connectors attached. Then standard 9-pin cables can link the control consoles with the connectors on the bus cable.
for Surround All connected Model 71 units will also go through a power-up sequence after mains power is applied to the Model 76D. Each of the Model 71’s three LEDs will light momentarily. After these LEDs have been lit, the device address will be shown briefly using the dim and reference level LEDs, as shown in Figure 7 in the Configuration section. When this is complete the Model 71 will begin normal operation and its status LED will light if communication is established with the Model 76D.
for Surround The configuration diagrams, located later in this section, give details on setting each parameter. An overview of each configurable parameter is provided in the following paragraphs. Entering and Exiting the Configuration Mode A small button is located on the back of each Model 77 Control Console, adjacent to its 9-pin female D-sub connector.
for Surround Model 77 units. Be sure that any selected address does not conflict with addresses to be assigned to Model 71 units. Stereo Input C Sample Rate Converter Circuitry associated with stereo input C can provide sample rate conversion (SRC) for digital audio signals connected to that input. The acceptable input range for sample rate conversion is very wide, but is dependent upon the output sample rate.
for Surround been selected for, as an example, soloing then the bass management filters will send any applicable low-frequency content to the post-fader subwoofer output. So in this case the solo function is really an “input channel” solo since the actual acoustical energy associated with that channel will be reproduced by both the main channel and the subwoofer loudspeakers. So while one is “soloing” a channel (or set of channels) two or more loudspeakers may be reproducing the signals.
for Surround the setting that provides a 75 ohm source impedance and a nominal output level of 1 Vpp would be correct. Post-Fader Surround/Stereo Monitor Output Type The source impedance and output level of the post-fader surround and stereo monitor outputs, as a group, can be configured. The information previously provided concerning configuring the pre-fader surround/ stereo input C direct monitor output type also applies to these outputs.
for Surround recognized. This is provided specifically so that unauthorized users won’t accidentally change the reference level while they experiment with the configuration mode. Only if you know the “secret” will you be able to store a new value. Overall Display Mode The Model 77’s 4-digit numeric display can be configured to display the post-fader surround and stereo monitor output levels in either an attenuation mode or an SPL mode.
for Surround Remote Dim Two configuration choices are associated with the remote dim function: disabled and enabled. To utilize the remote dim function simply configure it for enabled. Input Delay “lined up” accordingly. During normal StudioComm operation an operator can select the appropriate input delay for the display system currently being utilized.
for Surround When the surround to stereo downmix function is active the left surround (LS) input is routed to the left (L) post-fader monitor output; the right surround (RS) input is routed to the right (R) post-fader monitor output. By default the level of the LS and RS signals routed to L and R will be reduced (attenuated) by 3 dB. An alternate setting allows the levels to be reduced by 6 dB. (These settings can also be notated as –3 dB and –6 dB.
for Surround Post-Fader Monitor Output Level Offsets To provide assistance during room calibration, the relative output levels of the postfader surround and stereo monitor output channels can be adjusted over a limited range. The eight channels can be adjusted in 0.5-dB steps over a ±12-dB range. During configuration the displayed value represents the dB level difference as compared to the nominal output level.
for Surround Button Disable To disable the Model 71’s buttons, simultaneously press and hold both the dim and reference buttons for two seconds. When the disable request has been recognized the LEDs above both buttons will flash rapidly. Release the buttons and they will no longer enable or disable their normal functions. To return the buttons to normal operation simultaneously press and hold both buttons for two seconds at which time the two LEDs will flash rapidly. Figure 7.
for Surround Configuration—Entering and Exiting Configuration Mode and hold the configuration Press button for 2 seconds to enter or exit the configuration mode. These LEDs will light alternately when configuration mode is active. Issue 13, December 2020 Page 26 Model 76D/77 User Guide Studio Technologies, Inc.
for Surround Configuration—Model 77 Device Address, Stereo Input C Sample Rate Converter, and Post-Fader Stereo Monitor Output Press and hold the Mute/Solo button to display and configure the Model 77’s device address, stereo input C sample rate converter, and post-fader stereo monitor output. This LED displays the configuration of the stereo input C sample rate converter (SRC). LED not lit means SRC is disabled; LED lit means SRC enabled. Use the button to change the configuration.
for Surround Configuration—Bass Management and Mute/Solo Bass Management Mode This LED displays the configuration of the surround output bass management. LED lit means surround output bass management enabled; LED not lit means surround output bass management disabled. Use the button to change the configuration. See Note below. This LED displays the configuration of the stereo output bass management.
for Surround Configuration—Sync Source, Sync Input Termination, Audio-Synced-to-Video Sample Rate, and Monitor Output Types This LED displays the configuration of the sync input termination. LED not lit means sync input is not terminated; LED lit means terminated with 75 ohms. Use the button to change the configuration. Use the Channel Solo C and LFE buttons to select the pre-fader surround/stereo input C direct monitor output type.
for Surround Configuration—Reference Level and hold the Reference Level button for 5 seconds to take a “snapshot” Press of the level control’s setting at the time configuration mode was entered. The Reference Level LED will flash when the button is initially pressed and then light steadily when the “snapshot” has been taken. See Note below. Default: Reference level set for –60.0 dB post-fader monitor output level.
for Surround Configuration—Overall Display Mode, Reference Level in dB SPL, and Auto Reference Level Off When the Mute All button is pressed, use the Channel Mute/Solo L and R buttons to select the overall display mode. LED L lit means attenuation mode is selected; LED R lit means SPL mode is selected. Use the buttons to change the configuration. When the Mute All button is pressed, use the Reference Level button to enable or disable auto reference level off.
for Surround Configuration—Dim Level, Remote Mute All, and Remote Dim This LED displays the configuration of remote mute all. LED not lit means remote mute all is disabled; LED lit means enabled. Use the button to change the configuration. This LED displays the configuration of remote dim. LED not lit means remote dim is disabled; LED lit means enabled. Use the button to change the configuration. Use these buttons to select dim level.
for Surround Configuration—Surround to Stereo Downmix Levels and Pre-Fader Surround Monitor Output Mode These LEDs display the configuration of the pre-fader surround monitor output mode. LED L lit means output channels are pre-downmix; LED R lit means output channels are post-downmix. Use the buttons to change the configuration. Use this button to select the level change for the LFE channel when the surround to stereo downmix function is active. LED not lit means full attenuation; LED lit means –6 dB.
for Surround Configuration—Channel Pop Solo Mode Offset Levels Press and hold the Surround A button to display and select the channel pop solo up offset level. Press and hold the Surround B button to display and select the channel pop solo down offset level. When the Surround A button is pressed, use the level control to adjust the channel pop solo up offset level. The range is 0.0 to 12.0 in 0.5-dB steps.
for Surround Configuration—Input Delay Settings Press and hold the Stereo A button to display and select input delay A. Press and hold the Stereo B button to display and select input delay B. Use the level control to adjust the input delay. Range is from 0 to 340. The display shows delay in milliseconds at 48 kHz sampling rate. The value is scaled up or down for other sample rates. Default: Input delay 0 ms for both A and B. Model 76D/77 User Guide Studio Technologies, Inc.
for Surround Configuration—Post-Fader Monitor Output Level Offsets Press and hold the L button to configure the surround L level offset. Press and hold the R button to configure the surround R level offset. Press and hold the C button to configure the surround C level offset. Press and hold the LFE button to configure the surround Sub level offset. Press and hold the LS button to configure the surround LS level offset.
for Surround Configuration—Restore Factory Defaults and hold both the Surround/Stereo and Dim buttons for 5 seconds Press to restore Model 77 factory defaults. Once defaults have been restored, the associated LEDs will light. After the buttons are released, configuration mode will be exited and normal operation will resume. See Note below. Factory Defaults: Device address A1. Stereo input C sample rate converter enabled. Post-fader stereo monitor outputs can be enabled.
for Surround Operation Now that you’ve installed and configured the system, you’re ready to go. You should find operation very easy. However, taking time to study this section of the guide may prove valuable. Upon power up the system will return to the last operating condition, including the selected source, downmix modes, etc. As a precaution, however, the post-fader surround and stereo monitor output levels will always return to their minimum value.
for Surround 88.2, or 96 kHz.) Selecting a source with a sample rate of 44.1, 48, 88.2, or 96 kHz will resolve the issue and normal operation will resume. Refer to the Technical Notes section of this guide for additional details. Downmix Two downmix functions allow users to perform “real-world” audio format compatibility checks. One function allows a surround (5.1) signal to be “folded down” (mixed) to stereo. The other allows a stereo signal to be converted to mono.
for Surround buttons control operation of the surround and stereo outputs, reference level, mute all, and dim functions. The rotary level control is used to manually set the post-fader surround and stereo monitor output levels. These buttons and the rotary control do not impact the pre-fader surround and stereo input C direct monitor outputs. Surround and Stereo Outputs The surround/stereo function allows selection between two different loudspeaker systems.
for Surround Mute All Pressing the mute all button causes the output channels associated with the postfader surround and stereo monitor outputs to mute. The 4-digit display indicates the mute condition by showing four dashes (– – – –). The mute all button is always set to “latch” the function on and off. The LED associated with the mute all button will light whenever mute all is active. Note that if mute all is enabled via the remote mute all function, the mute all LED will flash.
for Surround attempts to set the output level for less than –70.0 dB, the post-fader surround and stereo monitor output channels will automatically mute. As previously discussed, the 4-digit display indicates the mute condition by showing four dashes (– – – –). If the mute all function is active the rotary level control won’t have an impact on the post-fader surround and stereo output levels.
for Surround During normal operation, press and hold the Mute/Solo button to view and change the solo mode and input delay settings. This LED displays the current setting of the solo mode. LED not lit means normal; LED lit means channel pop. Press the button to change the mode. This LED displays the current setting of the input delay. LED not lit means input delay A is selected; LED lit means input delay B is selected. Press the button to change the setting.
for Surround in positive numbers. These numbers are intended to represent the sound pressure level in dB SPL, a figure that should directly relate to the actual sound pressure level that the surround or stereo loudspeaker system is presenting to users. (Typically, the level value would actually be in dBC, the C-weighted sound pressure level.
for Surround monitor output levels. Its operating characteristics are identical to those of the Model 77 Control Console, discussed earlier in this section. Dim The dim function allows the post-fader surround and stereo monitor output levels to be reduced by a fixed amount. Its operating characteristics are identical to those of the Model 77 Control Console, discussed earlier in this section. An indication is provided should the dim button be pressed when button operation has been disabled.
for Surround “black” signal will allow most connected equipment to continue to function correctly, of course with no meaningful audio signal present. As soon as a valid sync signal is again connected to the Model 76D the monitor outputs will automatically switch to their correct sample rate and audio signals will again be present. Power Down Great care was taken in the Model 76D’s design to minimize the chance that clicks, pops, or other objectionable audio signals will be present on the monitor outputs.
for Surround Error Code Err4 Err4 will display if communications with a central controller has been established but that specific central controller is not compatible with the Model 77. For example, Err4 will display if a Model 77 has been connected with a Model 780-Series central controller. Sample Rate Conversion (SRC) Circuitry associated with stereo input C can provide sample rate conversion (SRC) capability.
for Surround 76D provides 12 volts DC for use by the control console’s circuitry. The DC output is current-limited to minimize the chance that a short-circuit condition will damage the Model 76D’s circuitry. An asynchronous, bi-directional data interface links the connected units. The RS-485 hardware connection scheme operates at a rate of 115.2 kbit/s and uses an 8-N-1 data format.
for Surround Specifications Model 76D Central Controller General Audio: Supported Sample Rates: 32, 44.1, 48, 88.2, 96, 176.4, and 192 kHz Word Length: 24 bits maximum Bass Management: Supported Sample Rates: 44.1, 48, 88.
for Surround Dimensions: 19.00 inches wide (48.3 cm) 1.72 inches high (4.4 cm) 7.00 inches deep (17.8 cm) Mounting: one space (1U) in a standard 19-inch rack Weight: 3.6 pounds (1.
for Surround Appendix A—Connection Pin-Out Charts Connections TASCAM® Signal Channel High (+) Signal Low (–) Shield Pre-Fader L/R 1 24 12 25 Pre-Fader C/SUB 2 10 23 11 Pre-Fader LS/RS 3 21 9 22 Stereo Input C Direct 4 7 20 8 Post-Fader L/R 5 18 6 19 Post-Fader C/SUB 6 4 17 5 Post-Fader LS/RS 7 15 3 16 Post-Fader Stereo 8 1 14 2 Notes: 1) All signals transformer-coupled digital audio; selectable for balanced or unbalanced AES3 compatibility.
for Surround Appendix B—Sync Input Sources The Model 76D’s sync input has been tested and confirmed for correct operation with the following sync signals: Word Clock: Square wave signal with rate of 32, 44.1, 48, 88.2, 96, 176.4, or 192 kHz. DARS (AES11) or AES3: Signal with sample rate of 32, 44.1, 48, 88.2, 96, 176.4, or 192 kHz. Bi-Level and Tri-Level Video: See table below. Video Format Video Format, continued NTSC (“Black Burst”) 1035i/59.98 Hz PAL (“Black Burst”) 1035i/60 Hz 525i/59.
